The primary function of this Core is to maintain cell lines and derived RNA for phenotyping studies by the PAAR investigators. The Core has created a total of 214 LCLs from sibling pair donors, and maintains 73 FCLs and 215 LCLs purchased from the Coriell cell repository. The latter were created from large families (CEPH/Utah). In compliance with Coriell policies (locus.umdnj.edu/ccr/comnVorder.html). Coriell cell cultures and DNA are not shared nor are they distributed. In contrast, cell lines, RNA and DNA from sibling pairs generated at UC are shared between institutions. The 214 cell lines from sibling donors include a number of ethnic groups: 51 European, 141 African American, 11 Hispanic, and 11 from other ethnic backgrounds, in contrast, the 215 cell lines from the CEPH collection are primarily European- Americans. The advantage to the CEPH collection is the publicly available genotypic information (landru.cephb.fr/cephdb/) and greater statistical power when using large pedigrees, whereas the advantage to the sibling pair collection is the collection of African Americans and Hispanics. FCLs are used for studies in cases where the expression levels of specific genes are higher relative to LCLs. The Cell Line Core is used by several Projects, Platforms, and Cores within PAAR. The Core is used by the CRC, CS, and CYP3A Projects; it interacts with the SDDA and Molecular Cores, and has provided DNA and RNA for the DR and WG Platforms.